40 JOHAN HJORT. M.-N. Kl. 



is no longer 8 " but 7 '*, and during the Spring (April) it sinks as 

 low as 6 ". 



The surface becomes warmed up again during the Spring. By 

 this a minimum becomes developed which lasts until the Summer 

 warmth is able to transplant itself to such a depth, that the tempera- 

 ture commences to fall from the surface to the deep. 



